Someone on the English Wikipedia pointed out that there may be a problem with
how "My Contributions" works. When one chooses to see to show, for example,
one's last five hundred edits, the user's last five hundred edits (-1 to -500,
I'll say) correctly show. However, when the person goes to the next page, edits
-500 to -999 are shown instead of -501 to -1000. Presumably, this error
continues so that edits -999 to -1498 are shown, followed by -1498 to -1997,
then -1997 to -2496, etc.